The proposed Phase I research will demonstrate the technical merit and feasibility of using computer-assisted analysis of red blood cell volume distributions in the diagnostic evaluation of anemia. Current automated hematology analyzers measure the volume of each red cell, providing the red cell volume distribution. Procedures developed by our consultants, McLaren and Brittenham (19,20,21), have now been adopted by the Expert Panel on Cytometry of the International Committee for Standardization in Hematology (ICSH) for inclusion as an ICSH Reference Method in their recommendations for the standardization of cell size distribution analysis (12). The major goal of the project is to adapt the standardized cell volume analysis protocol for routine use with commercially available automated hematology analyzers operating in a clinical laboratory. The computer programs of the consultants will be adapted for use with a microcomputer system to produce statistical and graphical analyses of red cell volume data and a synopsis of potential diagnostic interpretations. A computerized standard protocol for the analysis of red cell volume distributions is urgently needed to make generally available the new diagnostic information derived from current electronic particle counters and would provide a clinically useful, cost-effective approach to improving the evaluation and management of anemia.